55.2-59 Fuel pump

[55Trucker]

Hi all. I have a 55.2 Chevy 3100. I last drove it in 2017, when I found I had to replace the fuel pump to get it going in the spring. The last couple of years it really hasn't been driven, just started a few times. I planned to drive it a lot this summer (now that I am retired!). Lo and behold, it started right up, but I only made it halfway down out road before it acted like it was starved for fuel and died. My wife towed me back, and I found that the fuel pump was not putting out any fuel when I ran the starter. The pump I put in in 2017 is an Airtex 4149. I always have ethanol fuel stabilizer in the tank. Any thoughts on why the pump would give out without much use after 3 years? Thanks!

[mr48chev]

From what I read on the can of SeaFoam the other day it is good as a stabilizer for a year.

I'd be checking the gas to make sure that it smelled like gas an not like varnish. I've had just far too much trouble with old gas to even want to risk it anymore.

You haven't by chance changed the gas cap lately? Since you last drove it any distance? I had a lot of trouble with "vented" caps that weren't vented including walking a mile to a gas station thinking I had ran out of gas. Only to figure out that my brand new shiny vented gas cap wasn't vented.

Last, how much gas was actually in the tank? All those starts and running for a few minutes may have used up the gas that was in it.

Simple things first:
Make sure that it actually has gas in it.

It wouldn't be a bad idea to drain the tank and put a couple of gallons of fresh gas in it.

Fuel filters are inexpensive and cheap insurance. I'd just replace the filter (s) and call it maintenance.

I've never seen anything on how ethanol does with rubber with the stabilizer ion it. It's one of the worse jokes forced on people with old cars to make midwestern corn farmers rich that has come around though.

[1project2many]

Any thoughts on why the pump would give out without much use after 3 years?

Yes, if it is the pump.

A mechanical pump uses a diaphragm that moves as the arm on the pump moves. The diaphragm has to be flexible. There are still many fuel pumps hanging around in warehouses and in parts store inventory that use a rubber compound which is not compatible with ethanol. You need to get a pump that is ethanol compatible if you use E5 or E10.

Otherwise, I'd agree that you should ensure the cap isn't creating a vacuum in the tank and that you have a good supply of fuel on a line that is not accidentally sucking air.

[dsraven]

I have seen the valves on the mechanical pump stick to their seats inside the pump from sitting. sometimes a shot of low pressure air in the tank filler will force the valves off their seats and the thing will work like it should again. 1project makes a valid point on the compatibility of the rubber and valves in the pumps. not a huge calling for fuel pumps on these old trucks so you may have gotten old stock. you may have old fuel but it should still pump it just may not work well and will usually foul the plugs. you could have a plugged filter, a collapsed rubber fuel line etc. maybe try the "air pressure in the tank filler" idea to see if you have a clear passage from the tank to the pump outlet and then do the pressure and flow test once that is established. a tank drain and some fresh fuel first would be good too. there should be a short length of rubber hose under the floor where the fuel line goes from the tank behind the seat over to the steel line on the frame rail. a great spot for an inline filter too. that is if the fuel tank is still in the stock location.

[_Ogre]

possible rust in your tank. the diaphragm just goes in/out, the pumping action is by 2 check valves allowing one directional flow. any rust in the check valve (aka rubber flap) can hold the valve open. a fuel filter before the pump will fix this.

[55Trucker]

It was the fuel pump after all. I had an Intex on there, and I couldn't feel any vacuum while cranking the engine. Hard to believe but O'Reilly's had one in my hands at 8am on Saturday morning, about 12 hours after I ordered it. I first questioned the one they gave me - it didn't look the one on their website, which looked like the Intex. It looked like the Carter one. Of course it's made in Taiwan, not in the US. I put it in, cranked with the line disconnected from the carb, and caught a bunch of dirty fuel in a cup from the fuel line. I have a glass fuel bowl filter ahead of the carb. I plan to put one in before the pump now. Thanks all for your help.